Biquadratic exchange from susceptibility data in classical one-dimensional Heisenberg systems

We have investigated the magnetic susceptibility of three quasiclassical one-dimensional magnetic systems, CsMnBr3, (CH3)4NMnCl3 (TMMC), and CH3NH3MnCl3⋅2H2O (MMC), in their paramagnetic regimes. We find that a previous analysis in terms of a classical Heisenberg Hamiltonian does not provide an adequate description of the data at low temperatures where short-range correlations are high. We show that approximate quantum-mechanical corrections to …